Abstract: The Chang’e-3 was the first lunar soft landing probe of China. It was composed of the lander and the lunar rover. The Chang’e-3 successful landed in the northwest of the Mare Imbrium in December 14, 2013. The lunar rover completed the movement, imaging and geological survey after landing. The lunar rover equipped with a stereo vision system which was made up of the Navcam system, the mast mechanism and the inertial measurement unit (IMU). The Navcam system composed of two cameras with the fixed focal length. The mast mechanism was a robot with three revolute joints. The stereo vision system was used to determine the position of the lunar rover, generate the digital elevation models (DEM) of the surrounding region and plan the moving paths of the lunar rover. The stereo vision system must be calibrated before use. The control field could be built to calibrate the stereo vision system in the laboratory on the earth. However, the parameters of the stereo vision system would change after the launch, the orbital changes, the braking and the landing. Therefore, the stereo vision system should be self calibrated on the moon. An integrated self calibration method based on the bundle block adjustment is proposed in this paper. The bundle block adjustment uses each bundle of ray as the basic adjustment unit and the adjustment is implemented in the whole photogrammetric region. The stereo vision system can be self calibrated with the proposed method under the unknown lunar environment and all parameters can be estimated simultaneously. The experiment was conducted in the ground lunar simulation field. The proposed method was compared with other methods such as the CAHVOR method, the vanishing point method, the Denavit-Hartenberg method, the factorization method and the weighted least-squares method. The analyzed result proved that the accuracy of the proposed method was superior to those of other methods. Finally, the proposed method was practical used to self calibrate the stereo vision system of the Chang’e-3 lunar rover on the moon.

Abstract: The lunar exploration phase III mission is a part of the China Aerospace Science and Technology Corporation’s lunar exploration program that will perform a soft-landing and sample return from the Moon to test the key technologies that are required for human lunar missions. This paper focuses primarily on the trajectory design and orbital launch window generation for a lunar probe that are consistent with the constraints imposed by third phase of lunar exploration. Two categories of trajectories are explored: Earth-to-Moon and Moon-to-Earth. With the patched conic technique, the analytical and modified analytical models of the transfer trajectories are developed. The requirement of high-latitude landing for the return phase trajectory is considered in the modified model. By varying the initial input conditions and with a fast convergence iteration scheme, different characteristics of the transfer trajectory are generated. The orbital launch windows are established to study the mission sensitivities to time and fuel consumption and to provide a launch timetable that is compatible with this mission’s requirements. The lunar surface stay time is analyzed for different conditions. The high-fidelity gravitational model is introduced to demonstrate the accuracy and convergence behavior of the analytical solution. The design method can also be used as a basis for the future human lunar missions.

Abstract: In order to obtain absolute heading angle and position, lunar rover needs the support of autonomous celestial navigation system (CNS). This paper proposes a sun observation based simultaneous celestial positioning and orientation (SCPO) algorithm for the lunar rover under stationary position. Firstly we measure the sun orientation by a sun sensor and the gravity orientation by an inclinometer; secondly combine them with sun ephemeris; finally solve this problem with quaternion estimation (QUEST). By analyzing affects of the sensor's system error (such as the installation errors, bias, etc.) and random noise under stationary conditions, these two types of errors can be eliminated using joint calibration. Executing the SCPO on the moon is demonstrated through simulation. The algorithm is carried out with an experiment on the earth surface, and results demonstrate the high consistency of our simulation.

Highlights: •The distribution and characteristics of lunar polar volatiles are mostly unknown.•A lunar rover mission is required to map the spatial distribution of polar volatiles.•A new concept of operations is required for a short duration lunar rover mission.•Field testing yields insights into science and operations for a future Moon mission.

Abstract: In recent years, the lunar explorer programs, suspended for a long time, have resumed again with the rapid development of low cost and high-level technologies. As a result, several nations have made a success of lunar exploration programs with their own orbiters. Unlike a satellite orbiting the earth, the optimal design of an onboard propulsion system of a lunar orbiter is a major issue because it is not simple to make the orbiter arrive accurately at another planet far from the earth. Hence, a close attention is required to select and develop an appropriate type of the onboard propulsion system based on given mission requirements of a lunar orbiter. To do this, this study first surveys several lunar orbiters launched since 1990 and their major mission requirements. Then, it summarizes the technical trends of the onboard propulsion systems of the recent lunar orbiters and their key design and performance specifications through trade-off studies. By comparing these features, the present study investigates which lunar mission requirements are critically important, and how they can effect on the overall performance of an onboard propulsion system. Based on these investigations the major objective of the present study intends ultimately to set up a fundamental baseline in selecting and developing an appropriate type of onboard propulsion system of a lunar orbiter.

Abstract: Returning to the Moon has kept gaining interest lately in the scientific community as a mandatory step for answering a cohort of key scientific questions.This paper presents a novel Lunar mission design to demonstrate enabling technologies for deep-space exploration, in accordance with the Global Exploration Roadmap and the National Research Council. This mission, named ALCIDES, takes advantage of some of the systems that are currently under development as a part of the HERACLES exploration architecture: these include the Orion module, the Space Exploration Vehicle, the Boeing Reusable Lander, the Ariane 6, the Falcon Heavy, the Space Launch System, as well as the Evolvable Deep-Space Habitat placed in EML2.A consistent part of the efforts in designing the ALCIDES mission accounts for innovative exploration scenarios: by analysing state of the art in robotics and planetary exploration, we introduce a mission architecture in which robots and humans collaborate to achieve several tasks, both autonomously and through cooperation.During this mission, high-performance mobility, extravehicular activity and habitation capabilities would be carried out and implemented. This project aims to demonstrate the human capability to live and work in the Lunar environment through the development of a long-term platform.We selected the Amundsen-Ganswindt basin as the landing site for multiple reasons: the possible presence of permanently shadowed regions, its position within the South Pole and its proximity to the Schrödinger basin. The main objectives of the ALCIDES mission are to study the Lunar cold trap volatiles, to gain understanding of the Lunar highlands geology through sampling and in-situ measurements and to study Human-Robotic interactions. In addition, factors such as psychology, legal issues and outreach regarding this mission were also considered.In particular, four traverses connecting the Amundsen crater with the Schrödinger basin were proposed, three of which to be performed by a tele-operated rover, and the remaining one to be carried out by a human crew with rover assistance. During these traverses, the rover will collect samples from several points of interest as well as perform in-situ measurements with a suite of instruments on board, helping to locate a convenient place for future human habitation.The ALCIDES mission results will help the scientific community to better understand the Moon and to take advantage of its resources for future space exploration. Gaining this knowledge will allow us to move forward in the development of systems and capabilities for manned missions to Mars and beyond.

Abstract: The paper provides an overview of the conceptual design of the Lunar Rover conceived by Team Italia for the AMALIA Mission, candidate for the Google Lunar X Prize Challenge. The name of the mission is an acronym of the Latin language sentence “Ascensio Machinae Ad Lunam Italica Arte”.With the Lunar Challenge initiative, the X Prize Foundation intends to promote the involvement of private actors in the access to space, by endowing a prize to the first privately funded lunar mission covering a certain minimum distance on the Moon surface. Additional prizes are available in case of achievement of more challenging goals, like surviving lunar night, travelling for a longer distance, visiting areas of the first Apollo Missions.Although the AMALIA Rover Subsystems are the typical ones of an Exploration Rover, their design is highly influenced by the above depicted mission context. The followed design approach is closer to the one of a commercial mission than to an Institutional Space Exploration Mission one. It has to be noted that, for being compliant with GLXP rules, at least 90% of funds required for competing in the Prize has to come from private or non-governmental sources.The achievement of such challenging goals requires adopting suitable technical and programmatic solutions, having the need to optimize costs and schedule while still maximizing the probability of success.

Abstract: The real-time and high precision positioning of the lunar rover vehicle is an important step for lunar exploration and science. SBI (same-beam interferometry) is the differential very long baseline interferometry (VLBI) technology, which can be used in lunar exploration with its high precision and stability. In this paper, the relative positioning model of the lunar rover vehicle (LRV) to lunar module (LM) based on the SBI and extended kalman filtering (EKF) is developed and presented. Using the current Chinese VLBI network and the planed Chang'E-3, SBI observation data with an attainable precision of picoseconds and a sample interval of 4s are simulated. The LRV's relative position to the LM is then estimated by the least squares adjustment, EKF and an adaptive EKF, respectively. Results show that the Adaptive EKF performs the best real-time solutions with the accuracy of 1.86m in X direction, 0.33m in Y direction and 0.09m in Z direction, which can provide a good reference for real-time positioning of planed Chang'E-3 rover.

Abstract: Given the renewed interest in exploring and exploiting the resources of the Moon, this paper will explore the proposition that sustainability should be a fundamental consideration when formulating policy in respect of regulating lunar activities. The current lunar regulatory framework, however, is a product of the Cold War and conceived at a time when sustainability and space environmental issues were not within the contemplation of policy makers. Yet there is an increasing awareness of the need for space sustainability within the space community and this should be focused towards shaping policy in respect of lunar exploration. Inherently linked to this is a new multi-sectored era of space activity with emerging space nations and private companies competing alongside established space actors to exploit the natural resources of the Moon. Disputes over legally binding methods of lunar resource allocation are harming the chances of obtaining any consensus regarding sustainable development. This discussion will show that there is no compelling evidence that commercial mining of the Moon will yield the vast natural resources that would make such a venture economically viable. It will be advocated that a policy of promoting the use of the moon for scientific and exploratory purposes by means of existing fora such as IDAC and using non-binding codes to create normative values of sustainability should be placed at the heart of lunar exploration policy.

Abstract: This study presents a trajectory optimization framework for lunar rover performing vertical takeoff vertical landing (VTVL) maneuvers in the presence of terrain using variable-thrust propulsion. First, a VTVL trajectory optimization problem with three-dimensional kinematics and dynamics model, boundary conditions, and path constraints is formulated. Then, a finite-element approach transcribes the formulated trajectory optimization problem into a nonlinear programming (NLP) problem solved by a highly efficient NLP solver. A homotopy-based backtracking strategy is applied to enhance the convergence in solving the formulated VTVL trajectory optimization problem. The optimal thrust solution typically has a “bang-bang” profile considering that bounds are imposed on the magnitude of engine thrust. An adaptive mesh refinement strategy based on a constant Hamiltonian profile is designed to address the difficulty in locating the breakpoints in the thrust profile. Four scenarios are simulated. Simulation results indicate that the proposed trajectory optimization framework has sufficient adaptability to handle VTVL missions efficiently.